Vent plug and electrolyte leveling device for aircraft storage batteries



M. A. KNIGHT Jan 5 1954- ROLYTE LEVELING DEVICE FOR AIRCRAFT STORAGE BATTERIES VENT PLUG AND'ELECT Filed July 8, 1952 2 SheetsSheet l 3 I A. mwaw M. A. KNIGHT VE T L G Jan. 5, 1954 N P u AND ELECTROLYTE LEVEL-INS DEVICE FOR AIRCRAFT STORAGE BATTERIES 2 Sheets-Sheet 2 Filed July 8, 1952 INVENTOR.

. MILTON A. XIV/6H? Patented Jan. 5, 1954 VENT PLUG ELECTROLYTE LEVELING DEVICE FOR AIRCRAFT STORAGE BAT- TERIES Milton A. Knight, Clifton, Va. I Application July. 8, 1952, Serial No. 297,793

' .7 Claims., 01. 136-478) (Granted under Title 35, U. S. Code (1952),

' sec. 266) The present inventionrelates to a vent plug and electrolyte leveling device for storage batteries for aircraft or other uses where thebattery 1 is likely to be inverted for an appreciable length of time.

Storage batteries of the lead and acid tYP require continuous venting to the atmosphere and when inverted require some means of venting thegases formed without the loss of electrol te.

The strong acids of the electrolytic fluid are corrosive and dangerous to equipment and, when lost, cause the battery to be damaged or destroyed. The present invention has for its principal object to provide for a vent plug which permits the venting'oi gases when the battery is either in normal position or inverted.

Another object of the invention is to provide for a vent plug which prevents the loss of electrolyte when the battery is inverted or tipped from its normal position.

A still further object is to provide a vent plug which prevents over-filling when water or electrolyte is being added to the battery.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawe ing in which:

Fig. 1 is a view in cross-section of the vent plug with the battery in vertical position.

Fig. 2 is a fragmentary top view partially in section taken on line 22 of Fig. 1.

Fig. 3 is a view in a section with the battery inverted.

Fig. 4 is a view in section with the battery tilted, and

Fig. 5 is a view with the vent plug removed in condition for re-filling the battery.

Referring to the drawing in which like numerals indicate like parts throughout the several views, battery case It has threaded filler and vent plug opening H with plug 12 composed of upper portion [3 and lower portion [4 and vent tube It threadably connected at [6. Vent tube I5 is seen to have a conical upper and upon which rests valve I! having gasket I8 when the battery is in an upright position.

An annular chamber I9 is formed between the valve l1 and the inner wall of the lower portion 14 of plug l2 and is connected by passages to chamber 2| formed by a recess 22 in case Ill and a ring 23 threadably secured therein. Other passages 24 connect chamber I9 with a liquid trap 25 formed. in the plug 12 which is open to atmosphere through passage 26 in the nipple 2l.... The lower portion M of plug !2 has a down.-

wardly extending tube 28 removably threaded thereon, the shoulder 29 of which cooperates with the seal 36 on'fiange 3i of ring 23 to block passage 32 when pressed by spring 33, as shown in Fig. Ring 23 has a groove in one side of its inner Wall and the shoulder 29 or tube 28'has lug 35 slidable in this groove, preventing undesired rotation of tube 28, the ring 23 being cemented or otherwise secured to case It in any conventional manner. 1

Portions l3 and i l of the plug 12 have differv ently pitched threads 38 andtfl, respectively, the thread of the lower portion It having a greater pitch, here shown in exaggerated view.

In operation, when the battery is .in uprigh position as shown in Fig. 1, gases produced by the operation of the battery are vented to atmosphere by passage 32, chamber 2|, chamber 19, passages 25, and passage 28. Should the battery. be inverted as in Fig. 3or tipped to a less than horizontal position as in Fig. i, the valve I! and seal l8 close passages 2 3 and the electrolyte 4| which may escape down the vent tube i5 is caught in the trap 25, later to be returned as the battery. is made upright. While in inverted position, gas is vented to atmosphere directly through the vent'tube l5 and the passage 25, it being understood that the battery electrolyte does notcompletely fill the cell but leaves a space for gas or air above. the cell as in conventional batteries, The optimum performance of the portion of the invention thus described is dependent upon the amount of electrolyte in the battery with regard to the dimensions of the battery cell space and the means for keeping the electrolyte at the proper level is seen in Fig. 5. Due to the threads 39 of the tube 28 having a greater pitch, as the plug [2 is unscrewed, the tube 28 is disconnected from the lower portion [4 of plug [2, allowing the spring 33 to press the shoulder 29 and seal 30 on the ring 23, closing passage 32. This seals the space 42 above the electrolyte 4| in the top of the cell and as electrolyte or water is poured in through tube 28 it reaches the level of the lower end of the tube 28 and then fills tube 28. When the plug i2 is screwed into the opening II, it lifts tube 28 to the position shown in Fig. 1, opening passage 32 and allowing the fluid in tube 28 to sink into the cell. The dimensions of the tube 28, liquid trap 25, vent tube l5 with respect to the cell are to be such that little fluid normally will enter the liquid trap as in Fig. 4, allowing for the normal expansion and evaporation the dangerous spill'ingi of the electrolyte in any position, allowing normal operation of the battery in aircraft during all attitudes of flight and.

maneuvers.

It should be understood, ofcou'rse,th'at-:the? foregoing disclosure relates to only" apreferred embodiment of the invention and that numerous modifications or alterations may be made'therein.

without departin from the spirit and the scope of the invention as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental? purposes without the payment of any royalties thereon'or therefor.

Iclaim:

1. A'closure for acontainer having a normal operating liquid level therein comprising a plug adapted tobe'removablysecured in an-opening in the top of the 'containeiya-chamber in said plug opening to atmosphere, a passage in said plug normally venting the space above the liquid level insaid container to said chamber, a vent pipe secured to said plug connecting said chamber to the space above theliquid level of the container in inverted position, and a gravity actuate-d valve reciprocal in said container operable to close said passage upon inversion of the container.

2. The device as set forth in claim 1 and a single liquid trap in said closure and positioned in said chamber constructed and arranged to trap and return to the container liquid spilling into said vent pipe upon inversion of the-container.

3. In a container having a normal operating liquid level therein, a filler cap and valve device comprising a closure removably secured in an opening in the top of the container, said closure having a chamber vented to atmosphere, a vent pipe secured to said closure connecting said chamber withthe space above the'liquid level of thecontainer while in inverted condition, a fluid conduit in said container surrounding said. opening and extending below the normal operating liquidlevel, said conduit having a port near the top thereof connecting the'space in said container exterior of said conduit to the space within said conduit, means in said closure defining a passage connecting said first-named space with said chamber, a first valve means reciprocal in said container operable to close said passage upon inversion of said container, a second valve means in' said container biased to:close said port in said fluid conduit, and means on said closure adapted to. open said second valve means upon seating of said closure in said opening.

4: The-device as set'forth in claim 3 in which saidlfiuidlconduitcomprises a first tube portion fixed to the top of said container and therewithin, and a second tube portion telescopically arranged within said first tube portion and slidable therein, said ifirstandsecond tube portions having an finingmeans in said closure upon inversion of.

said container.

6. The device as set forth in claim 4 in which.

said second valve means comprises a compressible seal between said inwardly and said outwardly, facing shoulders on said first and second. tube.

portions and a compressionspring in. saidcomtainer biased to press said shoulders together on.

said seal.

7. The deviceas set forthin claims in which said means adapted to open said second valve means comprises two threaded portions on said closure constructed andv arranged to coact one.

each with matching threads in the opening in the top of the container and with matching threadsv on the second tube portion, said threaded portions having dissimilarly pitched threads whereby upon seating of said closure in said opening said second tube portion is lifted against the compression of said spring.

MILTON A. KNIGHT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,977,506 Dodds Oct. 16, 1934 FOREIGN PATENTS Number Country Date 336,041 Great Britain Oct. 9, 1930 

